We propose research to study the effects of experimental myocardial ischemia on heart vascular exchange as determined by cardiac lymphatic transport of proteins, trace metals and enzymes. Two surgically prepared models will be used: an acute anesthetized cardiac lymphatic preparation and a chronic unanesthetized cardiac lymphatic preparation. Bypass cannulae will be used to continually perfuse the left anterior descending coronary artery and coronary sinus. The duration and extent of reduced coronary flow will be achieved by an external occluder on the cannula. Cannulae will be appropriately placed for monitoring of liver uptake and release of specific cations and proteins. The effects of partial or total occlusion and reperfusion on transport as evaluated by cardiac lymph flow, lymph content and blood content will be correlated with tissue content and resultant pathological changes. The transport effects in response to myocardial ischemia will be compared to alterations with cardiac lymphatic obstruction and following pharmacological interventions. The results on lymphatic dynamics and/or lymphatic insufficiency will be used to assess the clinical implications of these transport alterations in ischemic heart disease and may enhance our understanding of ischemic myocardial pathophysiology.